f-number equivalent between m43 and FF

Started Mar 25, 2014 | Discussions thread
crames Regular Member • Posts: 192
Re: SNAP! Where it is?

dwalby wrote:

crames wrote:

Upsampled noise looks noisier, not due to any change in the standard deviation but due to the way magnification shifts the visible frequencies in the noise to more sensitive regions of the eye's contrast sensitivity function.

By upsampling don't you create a condition where the noise in adjacent pixels is no longer uncorrelated?

Yes, the new pixels created when upsampling will be correlated with the surrounding pixels they were interpolated from.

When you bin a block of pixels you only achieve the sqrt(N) SNR improvement if the noise is uncorrelated over all the samples. Depending on the magnitude of the cross-correlation components of the noise you lose some or all of that processing advantage.

I don't follow you. When you bin you downsample. Are you talking about upsampling then downsampling? Why would you do that?

Post (hide subjects) Posted by
(unknown member)
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow